If oil is allowed to flow out of the compressor used in a refrigerating cycle to an outside cycle, problems such as insufficient oil present in the compressor and lowered refrigerating efficiency due to the oil circulating through the cycle together with the coolant.
Various structures have been proposed in the related art to address these problems. For instance, there is a structure proposed in the related art, which includes an oil separation chamber disposed on the outlet side of the compressor to communicate with the outlet chamber and an oil separation tube disposed in the oil separation chamber so as to separate oil present in the compressed coolant by causing the coolant containing the oil around the oil separation tube (patent reference literature 1)
In addition, there is a compressor with a working fluid passage through which the working fluid (coolant) is guided from the intake port into the intake chamber via a crankcase (swashplate chamber), adopting a structure that includes an oil separation plate installed in the crankcase (swashplate chamber) and separates/captures the oil mixed in the working fluid by causing the working fluid having flowed into the crankcase from the intake port to collide with the oil separation plate (patent reference literature 2).
The applicant of the present invention also previously proposed a compressor in which the working fluid is a guided from the intake port into the intake chamber via a crankcase. The compressor adopts a structure that includes at least an axial hole ranging along the axis of a shaft passing through the crankcase, and a radial hole ranging along the radius of the shaft so as to open into the crankcase, both formed in the shaft, with the working fluid having flowed into the crankcase guided into the intake chamber sequentially via at least the radial hole and the axial hole, so as to separate the oil in the working fluid that is about to flow from the crankcase into the intake chamber as the working fluid flows through the radial hole opening into the crankcase by using the centrifugal separation effect induced as the shaft rotates.    Patent reference literature 1: Japanese Unexamined Patent Publication No. 2005-23847    Patent reference literature 2: Japanese Unexamined Patent Publication No. 2000-45938